Residential gateway

A residential gateway is a small consumer-grade gateway which bridges network access between connected local area network (LAN) hosts to a wide area network (WAN) (such as the Internet) via a modem, or directly connects to a WAN (as in EttH), while routing. The WAN is a larger computer network, generally operated by an Internet service provider. Multiple devices have been described as residential gateways: Cable modem DSL modem FTTx modem IP-DECT telephone (base station) Network switch Smart home hub TV/VoD Set-top box Voice over Internet protocol (VoIP) analog telephone adapter Wired router Wireless access point Wireless router A modem (e.g. DSL modem, cable modem) by itself provides none of the functions of a router. It merely allows ATM or PPP or PPPoE traffic to be transmitted across telephone lines, cable wires, optical fibers, wireless radio frequencies, or other physical layers. On the receiving end is another modem that re-converts the transmission format back into digital data packets. This allows network bridging using telephone, cable, optical, and radio connection methods. The modem also provides handshake protocols, so that the devices on each end of the connection are able to recognize each other. However, a modem generally provides few other network functions. A USB modem plugs into a single PC and allows a connection of that single PC to a WAN. If properly configured, the PC can also function as the router for a home LAN. An internal modem can be installed on a single PC (e.g. on a PCI card), also allowing that single PC to connect to a WAN. Again, the PC can be configured to function as a router for a home LAN. A cellular wireless access point can function in a similar fashion to a modem. It can allow a direct connection from a home LAN to a WWAN, if a wireless router or access point is present on the WAN as well and tethering is allowed. Many modems now incorporate the features mentioned below and thus are appropriately described as residential gateways, such as some Internet providers which offer a cable modem router combo.